Apparatus for cooling loose material



3 Sheets-Sheet l Feb. 9, 1932. c. MITTAG APPARATUS FOR COOLING LOOSEMATERIAL Filed Oct. 30, 1926 /f 1/ /f f f///// l Feb. 9, 1932. c. MITTAG1,844,782

APPARATUS FOR COOLING LOOSE MATERIAL Filed oct. 30, 192e 5 sheets-sheet2 ation/441,11

f I l ,/f/ \h.

Feb. 9, 1932. c. MITTAG 1,844,782

APPARATUS FOR COOLING LOOSE MATERIAL Filed oct. so, 1926 s sheets-sheets .Patented Feb. 9, 19324v UNITED STATES PATENT. 'oFFlcE ,l CARLMITTAG,.OF MAGDEBURG, GERMANY, ASSIGNOR TO FRIED-EBU?? GBUSONWEBK,

A. G., F MAGDEBURG-BUCKAU, GERMANY APPARATUS FOB. COOLING LOOSE MATERIALApplication filed October 80, 1926. Serial No. 145,359.

This invention relates to devices for cooling loose material such asclinker from a cement kiln.

The clinker comes out of the kiln at a temperature of about 1000 C. andat the present time is usually carried oif and allowed to cooll withoutany. special provision for hastening the cooling. One object of thepresent invention is to provide an arrangement whereby the clinker canbe cooled down as quickly as possible after leaving the kiln.

Another object of the invention is to move the clinker slowly forward ina thin layer in the opposite direction to a stream of cooling air, themoving means being so constructed as to constantly turn the clinker overand over as it is moved forward, whereby all parts of the clinkerwill'be brought into contact with the cooling medium.

Another object is to pass the clinker to be cooled over a platformconstructed of material having high heat conductivity, and to passstreams of air over and under the platform, the upper stream taking theheat by direct contact with the clinker, wnlle the lower stream takes upheat transmitted through the platform.

If it is found desirable to increase the coolling effect by sprayingwater over the clinker this will be done at a point where the clinkerhas been cooled to a certain extent. The upper stream of air then not.only dries the clinker but also carries off. the evaporated water. Inthis case the combustion air is taken only from the lower stream of air.

Other objects and advantages will appear from the followingspecification and accompanying drawings in which certain embodiments ofthe invention are described and ilvlustrated by way of example. In thedrawings Fig. 1 is a vertical longitudinal section of one form of thedevice,

Fig. 2 is a cross section on the line 2 2 of Fig. 1f,

Fig. 3 is a longitudinal section of another form of the invention,

Fig. 4 is a longitudinal section of still another form of the invention,

Fig. 5 is a plan view of a portion of the chain conveyor shown in Figs.1, 2, and 3, and

Fig. 6 is a plan view of a portion of another form of conveyor which maybe used in either the device shown in Figs. 1 and 2, or that of Fig. 3.

The arrangement according to Figs. 1 and 2 will be described first. Overthe discharge end of the rotary kiln 1 is arranged a hood 2 theconnection between the two being constructecl so as to exclude air asfar as possible. The bottom of the hood opens into a hole 3 in the top 4of a housing 4. Partitions 5 and 6 extend downwardly from the top 4 onopposite sides of the hole 3 and form, to ether with the side walls 7and 8 of the housmg 4', a shaft 5. At a short distance below the lowerends of partitions 5 and 6 is arranged a platform 9. These parts are allmade of re brick to withstand the high temperature of the clinker. Y

Beyond the end of platform 9 extends a metallic shelf 10. A conveyor 11is mounted on sprockets 12 and 13 so that its upper flight extends alongthe top of platform 9, 10 and its lower flight passes under the same.The

sprocket 12 is connected by means of suitable gearing 14 to a variablespeed motor 14 which moves the conveyor in the direction indicated bythe arrow m. The clinker falls from the kiln 1 through hood 2 and shaft5 and piles up on the platform 9. The upper flight of the conveyorpasses through the bottom of the pile of clinker and spreads the sameout into a thin layer on the surface of the shelf 10.

The speed of the conveyor isso regulated that there is always asufficient pile of clinker extending into the shaft 5 to seal the spacebetween platform 9 and the lower ends of partitions 5 and 6.

On the top 4 is arranged a blower 15', the suction conduit 16 of whichpasses through the top, and the exhaust conduit 17 of which opens intothe atmosphere. A partition 18 is arranged a short distance above theshelf 10 formin a passage 19, and a wall 20 seals the end of space 21.The air drawn in by the blower 15 must therefore pass along the passage19 in close contact with the clinker and then back through space 21 tothe blower.

A second blower 22, also mounted on top 4, has an exhaust conduit 23opening into the hood 2 and a suction conduit 24 opening into a chamber25 communicating with the passage 26 below platform 9, 10. The blower 22supplies air for combustion, which has been preheated by contact withplatform 9, 10, to the kiln 1, and also serves to blow fuel, such ascoal dust, which is fed from hopper 27, into the kiln.

The cross bars 28 of the conveyor 11 are constructed as shown in detailin Fig. 5, their upper surfaces being in the form of a series of plowshares. As these shares are drawn through the layer of clinker they constantly turn it over and over as they move it slowly forward, so thatall the particles of clinker are brought in contact with the cooling airin passage 19 andalso with the shelf 10 cooled by the air passingthrough space 26. A bar having right hand plow shares is followed by onehaving left hand plow shares so that the material is kept evenlydistributed over the surface of the shelf. The cooling of shelf 10 canbe made more rapid by providing its lower surface with ribs 28.

`vTo speed the cooling still more a rose 29 may be provided forsprinkling the clinker. The water evaporates and is carried oil" by theair passing over the clinker. This water does not get into thecombustion air which is drawn only from the lower passage 26. Flapvalves 29', 30 are provided for regulating the flow of air through eachblower. The clinker drops from the end of shelf 10 into a conveyor 37 ofany suitable form. A sight hole is provided at 39 for observing theheight of the pile of clinker which can be regulated by changing thevariable speed motor 14. This is necessary because the amount ofdischarge from the kiln is not constant.

If water is not to be used for cooling, the arrangement `shown in Fig. 3ma be used. This apparatus is exactly like the first described except inthe details which will now be pointed out. The single blower 31 has asuction conduit extending through top 4. Its exhaust conduit isbranched, one branch, 32 leading to the hood 2 and the other, 33 openinginto the atmosphere. The flap valves 34 and 34 are provided forregulating the quantity of air passing into the kiln. The space 25 isconnected to the space 21 by means of a by-pass 35 in which is arrangeda flap valve 36 for regulating the proportion of air passing throughpassages 19 and 26. A valve 37 may also be provided for regulating thetotal flow of air through the blower. With this arrangement one bloweris eliminated without sacrificing any facility of regulation.

In Fig. 6 another form of conveyor is shown which Consists of aplurality of chains 38 each of which bears a series of plow shares 39.In this form also a transverse series of right hand plow shares isfollowed by a transverse series of left hand low shares. The exact formof the system o plows used is not important,lthe essence of this part ofmy invention being a device which will turn the material over and overas it moves it forward so as to bring all the particles of clinker incontact with the cooling media.

A particularly desirable form of the invention, especially for smallkilns, is shown in Fig. 4. In this case again the kiln 1 discharges intothe hood 2 'which communicates at the bottom with a hole 3 in top 4. Theclinker is discharged into the pit 40 formed by walls 41. The bottom ofthe pit is a platform 42 of fire brick which forms the central portionof a rotary circular table. A ring shaped flange of metal, 44 completesthe surface of the table. The lower surface of the metal ring isprovided ,with a plurality of radiating ribs 45 which rest on a secondring 46 provided at its center with a hollow hub 47. The hub isrotatably mounted in a suitable hollow casting 48, the hub 47 andcasting 48 having flanges 47 and 48 respectively, between which areinterposed ball bearings 62. The table is rotated by means of gears 49,50, 51 and 52 driven by a suitable source of power. Air is sucked inthrough the space between rings 44 and 46 into the hollow hub 47 andcasting 48, thence through conduit 53, by blower 54. The exhaust conduitof blower 54 opens into hood 2. A second blower 57 draws air over theclinker through a space formed between a stationary upper plate 55 andthe surface of the table, thence through conduit 56, and discharges itinto the atmosphere. The plate 46 and hub 47 and the plate 55 correspondin this embodiment to the housing 4 of the first two forms shown, thespace between .these parts being divided by the ring 44 and platform 42into two compartments. A series of stationary plows 58 are arranged onradiating beams 59. The plows turn the material over and over as theymove it outward from the center of the table. A water sprinkler 61 canalso be used with this form of apparatus. The material is dischargedfrom the periphery of the table by means of a stationary scoop 60.

Having described my invention, I claim:

1. Apparatus for cooling pulverulent or granular material comprising aplatform, an endless chain arranged soy that one span of the same passesover said platform, a system of plows on said endless chain, means fordumping the material onto said platform, means for moving said endlesschain to cause said plows to spread the material in a thin layer on saidplatform, to advance the material along the platform, and to plow thematerial over and over as it advances, and means for passing a coolingmedium in heat exchanging relation with the thin layer of material.

2. Apparatus for cooling pulverulent or granular material comprising aplatform composed of material having a high coeiiicient of thermalconductivity, means for spreading and advancing the pulverulent orgranular material in a thin layer along said platform, and means forpassing two separate streams of a cooling medium above and below saidplatform respectively, both in countercurrent with respect to the travelof the material.

3. The combination with a cement kiln of a cooling apparatus for theclinker discharged therefrom comprising a housing divided into twocompartments, at least a portion of the dividing partition thereof beingin the form of a platform composed of material having a high coefficientof thermal conductivity, means for spreading and advancing the clinkerin a thin layer along said platform, means for sprinkling water uponsaid thin layer of clinker, means for passing two separate streams ofcooling air through said compartments, both incounter current withrespect to the travel of the material, and means for conveying air fromthe compartment at the opposite side of the partition to said layer tothe kiln for combustion purposes.

4. Apparatus for cooling pulverulent or granular material comprising ahousing, a platform within said housing, at least a portion of saidplatform being'composed of material having a high coefficient of thermalconductivity, a shaft formed by walls extending from the top of saidhousing to within a short distance of said platform, said shaft beingadapted to receive and convey the loose material to said platform, thearrangement being such that the space within said housing is dividedinto two separate 'compartments by said platform, said shaft, and thematerial piled upon said platform below said shaft, an endless chainarranged so that one span runs over said platform and through said pileof material while the other span returns under said platform, means onsaid chain to carry the loose material forward and spread it in a thinlayer upon said platform, and means for causing two separate streams ofcooling medium to pass through said two chambers in counter current tothe loose material.

5. In an apparatus for cooling pulverulent or granular materialdischarged from a kiln, a platform comprising a section composed of arefractory substance positioned to receive directly the materialdischarged from the kiln and a section composed of a substance having ahigh coefficient of thermal conductivity, means to move the materialfrom the receiving section and over the other section in a thin layer,and means to cause two separate streams of cooling air to pass above andbelow the platform in counter current to the travel of the material.

6. In an apparatus for cooling pulverulent or granular material, ashaft, a substantially horizontal platform beneath the shaft, said shaftand a portion of the platform being adapted to receive the material asit is discharged from a kiln, means for withdrawing the material fromsaid platform portion and passing it in a thin layer over anotherportion of the platform, said other portion being composed of asubstance having high thermal conductivity and means for forcing air inseparate and distinct currents above and below the platform in countercurrent to the travel of the material.

7. The combination with a kiln adapted to produce hot pulverulent orgranular material, of apparatus for cooling said material comprising ashaft, a substantially horizontal platform beneath the shaft, said shaftand a portion of the platform being adapted to receive the material asit is discharged from the kiln, means for passing the material in a thinlayer over another portion of the platform, said other portion beingcomposed of a substance having a high thermal conductivity means forforcing air in separate and distinct currents above and below theplatform in counter current to the travel of the material, a sprinklerarranged to discharge above the platform and a conduit for conductingthe air emerging from the lower side of the platform to the kiln forcombustion purposes.

8. Apparatus for cooling pulverulent or granular material, comprising arotary table havingsacentral section composed of refractory materialadapted to receive the hot material, and a surround section composed o fa substance having high thermal conductivity, plates above and belowsaid table .in spaced relation forming two air conduits upon oppositesides of said table, sa1dyconduits being open at the edge of the table,means for drawing two separate currents of air through said conduitstoward the center of the table, and stationary shovels arranged abovesaid table and adapted to dig the material away from said centralsectlon as the table rotates and to advance the material in a thin layertoward the edge of the table.

9. Apparatus as described in claim 8 1n which said rotary table ismounted upon a .hollow hub communicating with the air conduit under saidtable and `in which a suction fication is signed.

CARL MITTAG.

